Thanks for the reply. I have multiple calendars in the activities. The one I am using on the activity is China where holidays are Saturday and Sunday.

Now, When the system creates network from Sales order the standard network is picked and same calendars maintained in it as well. The problem here is China is having holiday on the date when the system is scheduling the activity and hence can not work on that date. Also calendar is configured for same to show weekend or weekly off on that day.

My question is why the date is picked even if it is holiday ? About the warning message yes I can override it but I just showed it to confirm it is holiday and system does consider as holiday.

In assembly processing we can see the end date is only passed from SO, correct me if my understanding is wrong. The end date is working day and basically its delivery date for the customer. based on those dates and the maintained relationship the backward scheduling calculating the dates but I am surprised to see the date on weekend.

I need to check with SAP but wanted to check before reaching out to SAP if this is only consulting issue ?

the system behaved properly and gave you the information that the date you entered is a non-working day but you entered it anyway. If you want to restrict the system then change the warning to an error.

When the system creates the network using assembly processing, this date is picked without any manual intervention. Do you mean that the Warning message is actually suppressed by system itself or ignored and the date is used ?

Here we are not creating this manually, the dates are populated based on relationship.